title: In vitro antifungal susceptibility profiles and genotypes of 308 clinical and environmental isolates of Cryptococcus neoformans var. grubii and Cryptococcus gattii serotype B from north-western India.
abstract: Cryptococcus neoformans and Cryptococcus gattii are aetiological agents of cryptococcosis, a major opportunistic systemic mycosis of increasing global importance. This study reports the antifungal susceptibility profiles of clinical and environmental isolates of C. neoformans var. grubii, genotype VNI/AFLP1 (n = 246), and C. gattii serotype B, genotype VGI/AFLP4 (n = 62), originating from patients and environmental sources in north-western India. All of the C. neoformans var. grubii and C. gattii isolates were mating type α. Using the broth microdilution method, both species were found to be susceptible to the antifungals tested except for two clinical C. neoformans var. grubii isolates that were resistant to 5-flucytosine (MIC >64 µg ml⁻¹). Data on the geometric mean of MICs revealed that C. gattii was significantly less susceptible than C. neoformans var. grubii to fluconazole, itraconazole and voriconazole (P<0.0001). In addition, the MIC₉₀ of C. gattii was twofold higher than that of C. neoformans var. grubii for fluconazole, itraconazole and voriconazole. However, no statistically significant difference in susceptibility of the two Cryptococcus species was observed against amphotericin B and 5-flucytosine. Furthermore, the environmental C. neoformans var. grubii isolates were significantly less susceptible to fluconazole, itraconazole and 5-flucytosine (P<0.0001) than the clinical isolates. A continued surveillance of antifungal susceptibility of clinical and environmental strains of C. neoformans and C. gattii is desirable to monitor the emergence of any resistant strains in order to ensure more successful therapy of cryptococcosis.
authors.affiliation: Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi 11007, India.
authors.forename: Anuradha
authors.initials: A
authors.lastname: Chowdhary
authors.affiliation: Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi 11007, India.
authors.forename: Harbans Singh
authors.initials: HS
authors.lastname: Randhawa
authors.affiliation: Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi 11007, India.
authors.forename: Gandhi
authors.initials: G
authors.lastname: Sundar
authors.affiliation: Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi 11007, India.
authors.forename: Shallu
authors.initials: S
authors.lastname: Kathuria
authors.affiliation: Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi 11007, India.
authors.forename: Anupam
authors.initials: A
authors.lastname: Prakash
authors.affiliation: Mycology Reference Laboratory, Department of Microbiology, Faculty of Medicine, Kuwait University, Safat, Kuwait.
authors.forename: Ziauddin
authors.initials: Z
authors.lastname: Khan
authors.affiliation: Institute of Infectious Disease Research, Michael G. DeGroote School of Medicine, and Department of Biology, McMaster University, Hamilton, ON L8S 4K1, Canada.
authors.forename: Sheng
authors.initials: S
authors.lastname: Sun
authors.affiliation: Institute of Infectious Disease Research, Michael G. DeGroote School of Medicine, and Department of Biology, McMaster University, Hamilton, ON L8S 4K1, Canada.
authors.forename: Jianping
authors.initials: J
authors.lastname: Xu
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology*; D003453:Cryptococcosis / Q000453:epidemiology / Q000382:microbiology*; D056285:Cryptococcus gattii / Q000145:classification* / Q000235:genetics; D003455:Cryptococcus neoformans / Q000145:classification* / Q000235:genetics; D025141:Drug Resistance, Fungal; D004783:Environmental Microbiology; D005838:Genotype; D006801:Humans; D007194:India / Q000453:epidemiology; D008969:Molecular Sequence Data
chemical_list: D000935:Antifungal Agents